Power transmitter



I. F. WEBB.

POWER- TRANSMITTER. APPLICATION-FILED FEB. 2. 1920.

Patented 00%. 241, 1922,

2 SHEETS-SHEET 1.

WITNESSES: INVENTOR I T "V;

ATTORNEY I. F. WEBB.

POWER TRANSMITTER. APPLICATION man FEB. 2. 1.920.

Patmtmadl. Oct. 24, W22.

2 SHEETS-SHEET 2.

INVENTOR MJTM W ATTORN N; lt atented Unit. lhllll.

'WEIEll-l, OF l'ElfiJTZfiBETlT-I, N

'rnnrrzre ooirtrnirmor nriraann'rrr, new a lY'DldTl-Elt THANSIMEE'IWER.

application filed February 2, 19950. Serial 1310. 855,823.

To all 107 m may concern:

Be it lrnown that ll, lnv no l3. d 'nnn, a citizen of. the United I'BSlCllILQ-F' at J. i i $3 .ithzabeth, in the county .0. Unionand state of New Jersey, have invented certain new and ,useful improvements in Power 'lransm tters, i: which the following is a speoil catron, reference being had therein to the acfcompanying drawings. 1 Tl'liS invention relates to power-transmitters of the treadle-controlled clutch-and brake type sewi. g machinepowentable installations to afford foot-control oi the sewing, machines.

An object otthe invention is toprovide a power-transmit or having improved operating. characteristics and adjustments enabling an operator to secure a rapid starting or stopping of the machine with a minimum oltellort, a A further object of the invention, is to provide a poWer-transmi tter which is toolproof, that is, not likely toget out oil order or adjustment, even though subjected to thoughtless or abusive treatment, i ,Eltill further, the invention hasfor an object to provide a powertransmitter which will operate automatically to maintain the driving belt at all times under the proper tension tor eflicient power'transmission and. which is so constructed as to prevent an in-.

experienced operator from applying amine ordinate or destructive tens1on to the dr1v-' ing belt.

. The invention further aims to provide a simple, sturdy and eflicient power-trans- Initter adapted, more particularly, for use with safety power-tables wherein the powertransmitters are commonly enclosed.

lhe invention in its preferred embodiment, comprises the; usual driving and driven clutch-disks with a friction. ring '01 leather or the like tl'ierebetween, and a treadle-controlled operating or starting lever tor forcing the disks into driving T612... t on with, one another.

rigidly, though adjustably, associated with the starting lever and is adapted to be,

forced. against the peripheral edge-portiou of the driven disk to stop the latter when pressure upon the treadle is reliev ed. ln the present instance, the transimtter proper is pivotally mounted upon an axis substantially vertically below the axis of rotation of the clutch-disks; the transmitter controlsuch as are coinmonlynsedin A brake-lever is ling rock-shaft carrying the starting and brake-arms being, disposed forwardly of the axis of the clutch-disks, whereby the treadlearod which is connected directly to the free end of the starting arm may extend substantially vertically downward to the usual, treadle, instead oi" extending downwardly at an unfavorable angle to the starting; arm and treadl e, as in prior constructions. t g

in the embodiment oi the invention illustrated, the transmitter is pivotally mounted upon a forwardly extending arm cast 1n tegral with the supporting bracket for the transverse parallel guard-rails which. house the transmitter and driving belt and support the top-boards or" the table. An expansion spring of predetermined strength is utilized to urge the ,ill'ttlltfillll'tllel forwardly about its pivot and tighten the driving belt to the proper 1 degree for ellicient power transmission. its the belt stretches in use, this spring automatically shifts the transmitter forwardly about its pivot to take up the slack and, as. the transmitter swings about its pivot, the upwardly extending or driven belt is slightly tightened, ratherthan loosened, since the pivot for the transmitter 18 below the axis oi" the pulleys. it bolt and screw device is provided for swinging the transmitter rearwardly to compress the belt-tensioning spring preparatory to applying a new belt. When a new belt is applied, it is maintained at the proper tension with out further care by the operator until the belt-tensioning spring expands to the limit allowed. When this occurs, a newbelt may be applied, or a section removed from the old belt to shorten it sulliciently. I

The invention also comprises the novel details of construction and arrangement oi parts hereinafter described. and particularly pointed out in the appended claims.

ln the accompanying drawings, Fig. 1 is a fragmentary transverse section through a power-table,showing the transmitter in side elevation. Fig. 2 is a fragmentary sideelc vation of the power-table showing;v the trans mitter in front elevation. F is areverse treadle connection for controlling. the trans mitten i For the purposes of the present disclosure the invention is embodied in a safety-type power-table comprising a table-top 1 which is supported by transverse guard-rails 22 arranged in pairs to form housings for the power-transmitting devices. The guardrails are sustained in spaced relation by brackets, one of which is shown at 3; eacn of said brackets being carried by a corresponding leg 4.

Referring to Figs. 1 and 2 it will be seen that the bracket 3 comprises a horizontal bar having flanges 5 at its opposite ends to which the guard-rails 22 are bolted. In the present instance the bracket is formed intermediate its ends with a forwardly extending arm 6 and an upwardly extending arm 7 having a vertical slot 8 at its free end.

Pivotally mounted upon the pin 9 at the free end of the forwardly extending arm 6 is the downwardly extending arm 10 of the transmitter-frame 11 in which is fixedly secured by means of the set-screw 12 the horizontal bearing pin 13 for the driving and driven clutch-disks 14 and 15, respectively. The driving clutch-disk 14 com.- prises a circular plate to the hub of which is secured a grooved pulley 16 in which runs the horizontal driving belt 17 extending from the usual central power-shaft (not shown) of the table. The driven disk 15 is in the form of a grooved pulley-wheel having a friction-ring 18 of leather let into its side face adjacent the driving disk 14$ The vertical belt 19 runs in the groove in the driven disk 15 and serves to connect the latter to the machine to be driven.

Referring to Fig. 1, it will be seen that the pivot 9 for the transmitter-frame 11 is below the bearing pin 13 for the clutchdisks. Movement of the transmitter to the left about the pin 9 will therefore tighten not only the horizontal belt 17 but also to an appreciable extent the vertical belt 19. This is an important consideration in preventing belt slippage inasmuch as both belts tend to stretch under operating conditions. The load, on the horizontal belt, however, is greater than that on the vertical belt, due to unavoidable losses in the transmitter.

The driving disk 14 is adapted to be forced into driving relation with the driven disk by means of a treadle-controlled starting arm 20 having a head 21 formed with a cam-face 22 which acts when drawn downwardly to push inwardly against the usual thimble 23 journaled in the hub of the driving disk in a manner well known and illustrated, for example, in the patent to Dimond et al.,.No. 582,851 of May 18, 1897.

The starting arm 20 is formed with an elongated sleeve-like hub 24 which turns freely upon the horizontal supporting pin 25 slidably. received within the apertured lug 26 and fixed in position therein by means of set-screws 26, Figs. 2 and 4, at the free end of the forwardly extending arm 27 of the transmitter-frame 11. Clamped upon the reduced inner extremity of the sleevelike hub 24 is the split hub 28 of the brakearm 29 carrying the brake-shoe 30 adapted to be drawn against the peripheral surface of the driven disk 15 by means of a spring 31 secured at one end to the brake-arm 29 and at its opposite end to an eye 32 in the transmitter-frame.

The extremity of the supporting pin 25 adjacent the frame-arm 27 is threaded to receive an adjusting nut 25. A collar 25 is fixed upon the opposite end of the pin 25 to confine the hub of the starting arm 20 against endwise movement during depression of said arm. The operative position of the starting arm may be adjusted laterally to bring the cam face 22 to the correct position relative to the thimble 23 by looseninp the set-screws 26 and the split hub 28 of the brake-arm and then turning the adjusting nut 25, thereby drawing the pin 25 and starting arm 20 to the right, Fig. 4. The hub 28 of the brake-arm, being in engagement with the lug 26, will not move during this adjustment, but the reduced extren'iity of the sleeve-like hub 24 will be forced further into the split hub 28; there being sutiicient clearance provided between the lug 26 and the extremity of hub 24 to permit of the desired range of adjustment.

Extending substantially vertically downward from an apertured car 33 on the head 21 is the treadle-rod 34 which is connected at its lower end to an arm 35 rigid with the usual pivoted treadle-plate 36. Pressure upon the toe of the treadle-plate serves to draw down the starting arm and establish driving relation between the clutch-disks; the downward motion of the starting arm being limited by an adjustable stop-screw 37 which is threaded into an car 38 on the split hub 28 of the brake-arm and is adapted to strike the upper surface of the arm 27 of the transmitter-frmne. This stop prevents the application of excessive starting pressure upon the clutch-disks.

The hub 24 of the starting arm is formed with a depending lug 39 positioned in front of a lateral extension 40 of the brake-ar1n 29 there being an adjusting screw 41 threaded into said lug 39 for exerting pressure upon the brake-arm when the heel of the treadle is depressed by the operator to secure a quick stop. By providing a direct pressure exerting contact between the lug 39 and brake-arm I avoid any tendency of the reduced extremity of the hub 24 to slip relative to the split hub of the brake-arm. As the brake-shoe wears, the screw 41 may be turned to position the brake-arm nearer the driven pulley, without altering the position of the starting arm.

, 'Ihe transmitter-frame 11 is further provided with an apertured lug 42 through which passes a bolt 43, the threaded end of which rests in the slot 8 of the upwardly extending arm 7 and receives the wing nut 44. A coil-spring 45 is interposed between .thearm 7 and lug 4-2. This spring tends to turn the transmitter about its pivot 9 and is I sowound 'as to exert a predetermined tension on "the belt 17. The purpose of the wing-nut tl is essentially to compress the spring 4C5 preparatory to. putting on a new belt, after which the nut 44. may be unscrewed as .far as the cotter-pin 44: to permit the spring 45 to have full play in tensioning the belt to the proper degree and maintaining the belt under such tension until the latter eventually stretches so far that the wigenut comes into engagement with the arm 7. When this occurs, a new belt may be put on or a section removed fromv the old belt to shorten it the proper amount.

Having thus set forth the nature of the invention, what I claim herein is-- 1. In a power-table, the combination with a table-top, of a manually controlled powertransmitter mounted below the table-top and comprising driving and driven disks and.

a starting arm, horizontal and vertical driving and driven belts connected to said disks, a stationary transmitter support, a transmitter frame carrying said arm and disks and pivoted to said support at a point below the axis of said disks, and means for swinging the transmitter-frame about its pivot to tighten the driving belt. I e

2. In a power-table, the combination with a table-top, of a power-transmitter mounted below the table-top and comprising driving and driven disksand a starting arm,

a stationary transmitter support, a transmitter frame carrying said arm and disks and pivoted to said support at a point below the axis of said disks, and a spring tending to swingthe transmitter-frame about its pivot, thereby automatically maintaining the driving belt at the proper tension without necessitating frequent adjustment by the operator.

8. In a power-transmitter, in combination, driving and driven pulleys with means for establishing and interrupting driving relation betweenthem, a support, a frame carrying said means and disks and movably mounted on said support, a spring for shifting said pulleys relative to said support, whereby the driving belt may be automatically tensioned to the proper degree. and manually controlled means for shifting said transmitter in opposition to said spring.

4. A power-transmitter having, in combination, a support including forwardly and upwardly extendingvarms, a transmitterframe pivotally carried by the forwardly extending arm, driving and driven clutch disks and a starting arm carriedby said transmitter-frame, and a belt-tensioning connection between the transmitter'frame and the upwardly extending arm. 5. A. power-transmitter having, in combination, a support including forwardly and upwardly extending arms, a transmitterframe pivotally carried by the forwardly extending arm, driving and driven clutchdisks and a starting arm carried by said transmitter--frame, an expansion spring between the ti'ansn iitter-frame and the upwardlyextending arm, and means connecting said frame and upwardly extending arm for shifting the frame in opposition to said spring. I

6. A power-table having, in combination, a table-top, spaced guard-rails extending transversely of and supporting said tabletop, a bracket carrying said guard-rails, a

power-transmitter frame pivotally mounted on sald bracket, driving and driven clutch disks and a startmg arm mounted on said transmittenframe with the axes of said disks disposed above the axis of pivotal con nection between the transmitter-frame and said bracket, and means for shifting said transmittenframe about its pivot.

'7. In a power-transmitter, in combination,

driving and driven disks, rigidlyconnected starting and brake-arms for controlling said disks, and means for angularly adjusting said brake-arm relative to said starting arm.

8. In a power-transmitter, in combination, driving and driven disks, rigidlyconnected starting-and brake-arms for controlling said disks, and a screw for positively shifting said brake-arm relative to said starting arm.

9. Ina power-transmitter, in combination,

driving and driven disks, manually controlled starting and brake-arms, and a stop for limitingthe manual application of starting pressure to the starting arm.

10. The combination with driving and driven belts, of a shiftably mounted power- 1 transmitter including driving and driven.

pulleys with means for establishing and interrupting driving relation between them,

yielding means for shifting said transmitter toexert a constant tension on the driving belt, and manually controlled means for relieving the belt of the force exerted by said yielding means.

11. The combination with driving and driven belts, of a shiftably mounted powertransmitter including driving and driven pulleys with means for establishing and interrupting drivingrelation between them, a spring for shifting said transmitter in one direction. to tension the driving belt, and a screw device for shifting the transmitter in opposition to said spring preparatory to putting on a new belt.

12. In a power-transmitter, in combination, coaxial driving and driven pulleys with 'means for establishing and interrupting driving relation between them, said means including a starting arm for forcing one of said pulleys into driving relation with the other, a transmitter framecarrying said arm, and means for adjusting the Working position of said arm in a direction parallel to the axes of said pulleys.

13. In a power-transmitter, in combina- 10 tion, a transmitter-frame, driving and driven disks mounted on said frame in coaxial relation, a starting arm pivotally carried by said frame to turn about an axis parallel to the axis of said disks, said arm having a 15 cam face for forcing one of said disks into IRVING F. \VEBB. 

